Go to OIM EM -> Farm -> Identity and Access -> OIM -> oim(11.1.2.0.0) -> Log Files

Create "Create Like" odl-handler .
Give your handler a new name : "custom-odl-handler"
and
Give it a new file path and adjust other settings

After that come to Log Levels Tab

Loggers with Persistent Log Level State

Specify Loggers

Give a new name "com.deepak.dubey.oim.custom"

Apply

Associate the new Logger with the custom handler "custom-odl-handler" that you created in previous step


---------------In Code ----------------------


import java.util.logging.Level;
import java.util.logging.Logger;

private Logger logger=Logger.getLogger("com.deepak.dubey.oim.custom");

logger.finest("your debug statements");